US3873670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flue gas desulfurization in molten media
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1972-08-14
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Granted: 1975-03-25
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Expires: 1992-08-14
Abstract
Abstract Sulfur oxides such as sulfur dioxide as well as nitrogen oxides are removed from flue gas by contacting the flue gas at elevated temperatures with a molten medium containing an alkali or alkaline earth metal oxide of hydroxide, including mixtures thereof, in combination with a glass-forming oxide such as an oxide of boron. The mole ratio of alkali or alkaline earth metal oxide or hydroxide expressed as the oxide thereof to the glassforming oxide is preferably maintained in the range of at least one in order for the glass-forming oxide melts to act as an efficient absorbent for the removal of sulfur oxides. The molten media is regenerated in order to remove and recover the sulfur absorbed by the glass-forming oxide melts of the instant invention by reducing the metal sulfates and sulfites formed in the molten media to their sulfide form and thereafter contacting the metal sulfides with steam at temperatures up to about 2000*F. in order to recover the sulfur values as either an essentially dry, highly concentrated hydrogen sulfide stream or elemental sulfur, including mixtures thereof.
Inventors
- 👤 John J Dugan
- 👤 Israel S Pasternak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:10
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/16; C01B17/161; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/60; C01B17/02; C01B17/04; C01B17/05; C01B17/164; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
118 words
A PROCESS FOR REMOVING SULFUR OXIDE FROM A HOT COMBUSTION GAS WHICH COMPRISES CONTACTING SAID HOT COMBUSTION GAS WITH A MOLTEN MEDIA CONTAINING A GLASS-FORMING OXIDE SELECTED FROM THE GROUP CONSISTING OF OXIDES OF BORON, MOLYBDENUM, TUNGSTEN, PHOSPHOROUS AND MIXTURE THEREOF IN COMBINATION WITH AN ALKALI METAL COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL OXIDES, ALKALI METAL HYDROXIDES, ALKALINE EARTH METAL OXIDES, ALKALINE EARTH METAL HYDROXIDES AND MIXTURES THEREOF AT A TEMPERATURE IN THE RANGE OF FROM ABOVE ABOUT THE MELTING POINT OF SAID MOLTEN MEDIA TO ABOUT 2000*F., THE MOLE RATIO OF THE ALKALI METAL COMPOUND EXPRESSED AS THE OXIDE THEREOF TO THE GLASS-FORMING OXIDE BEING WITHIN THE RANGE FROM ABOUT 1 TO ABOUT 3.0.
Claim 2
Dependent Claim
118 words
A PROCESS FOR REMOVING SULFUR OXIDE FROM A HOT COMBUSTION GAS WHICH COMPRISES CONTACTING SAID HOT COMBUSTION GAS WITH A MOLTEN MEDIA CONTAINING A GLASS-FORMING OXIDE SELECTED FROM THE GROUP CONSISTING OF OXIDES OF BORON, MOLYBDENUM, TUNGSTEN, PHOSPHOROUS AND MIXTURE THEREOF IN COMBINATION WITH AN ALKALI METAL COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL OXIDES, ALKALI METAL HYDROXIDES, ALKALINE EARTH METAL OXIDES, ALKALINE EARTH METAL HYDROXIDES AND MIXTURES THEREOF AT A TEMPERATURE IN THE RANGE OF FROM ABOVE ABOUT THE MELTING POINT OF SAID MOLTEN MEDIA TO ABOUT 2000*F., THE MOLE RATIO OF THE ALKALI METAL COMPOUND EXPRESSED AS THE OXIDE THEREOF TO THE GLASS-FORMING OXIDE BEING WITHIN THE RANGE FROM ABOUT 1 TO ABOUT 3.0.
Claim 3
Dependent Claim
181 words
A process for removing sulfur dioxide from a hot combustion gas which comprises contacting said combustion gas with a molten media containing a glass-forming oxide selected from the group consisting of an oxide of boron, phosphorus, molybdenum, tungsten and mixtures thereof in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof wherein the mole ratio of the alkali metal compound expressed as the oxide thereof to the glass-forming oxide is within the range from about 1 to about 3, at a temperature in the range of from about above the melting point of said media to about 2000*F. in order to absorb the sulfur dioxide in said molten media in the form of sulfur compounds selected from the group consisting of alkali metal sulfites, alkaline earth metal sulfites, alkali metal sulfates, alkaline earth metal sulfates and mixtures thereof; reducing said sulfur compounds to their corresponding sulfide form and thereafter contacting said sulfides with steam at a temperature up to about 1800*F.
Claim 4
Dependent Claim
181 words
A process for removing sulfur dioxide from a hot combustion gas which comprises contacting said combustion gas with a molten media containing a glass-forming oxide selected from the group consisting of an oxide of boron, phosphorus, molybdenum, tungsten and mixtures thereof in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof wherein the mole ratio of the alkali metal compound expressed as the oxide thereof to the glass-forming oxide is within the range from about 1 to about 3, at a temperature in the range of from about above the melting point of said media to about 2000*F. in order to absorb the sulfur dioxide in said molten media in the form of sulfur compounds selected from the group consisting of alkali metal sulfites, alkaline earth metal sulfites, alkali metal sulfates, alkaline earth metal sulfates and mixtures thereof; reducing said sulfur compounds to their corresponding sulfide form and thereafter contacting said sulfides with steam at a temperature up to about 1800*F.
Claim 5
Dependent Claim
111 words
A process for removing sulfur oxide from a hot combustion gas which comprises contacting said hot combustion gas with a molten media at a temperature in the range of from about above the melting point of said media to about 2000*F., said molten media containing an oxide of boron in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkaline earth metal oxides, alkaline earth metal hydroxides and mixtures thereof, the mol ratio of the alkali metAl compound expressed as the oxide thereof to the oxide of boron in said molten media being within the range from about 1 to about 3.
Claim 6
Dependent Claim
111 words
A process for removing sulfur oxide from a hot combustion gas which comprises contacting said hot combustion gas with a molten media at a temperature in the range of from about above the melting point of said media to about 2000*F., said molten media containing an oxide of boron in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkali metal hydroxides, alkaline earth metal oxides, alkaline earth metal hydroxides and mixtures thereof, the mol ratio of the alkali metAl compound expressed as the oxide thereof to the oxide of boron in said molten media being within the range from about 1 to about 3.
Claim 7
Dependent Claim
16 words
The process of claim 3 wherein the basicity of the molten media is at least 0.40.
Claim 8
Dependent Claim
172 words
A process for removing sulfur dioxide from a hot combustion gas which comprises contacting said combustion gas with a molten media at a temperature in the range from above about the melting point of said media to about 2000*F. in order to absorb the sulfur dioxide in said molten media in the form of sulfur compounds selected from the group consisting of alkali metal sulfites, alkaline earth metal sulfites, alkaline metal sulfates, alkaline earth metal sulfates, and mixtures thereof; reducing said sulfur compounds to their corresponding sulfide form and thereafter contacting said sulfides with steam at a temperature up to about 1800*F., said molten media containing an oxide of boron in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof, the mol ratio of the alkali metal compound expressed as the oxide thereof to the oxide of boron in said molten media being within the range from about 1 to about 3.
Claim 9
Dependent Claim
172 words
A process for removing sulfur dioxide from a hot combustion gas which comprises contacting said combustion gas with a molten media at a temperature in the range from above about the melting point of said media to about 2000*F. in order to absorb the sulfur dioxide in said molten media in the form of sulfur compounds selected from the group consisting of alkali metal sulfites, alkaline earth metal sulfites, alkaline metal sulfates, alkaline earth metal sulfates, and mixtures thereof; reducing said sulfur compounds to their corresponding sulfide form and thereafter contacting said sulfides with steam at a temperature up to about 1800*F., said molten media containing an oxide of boron in combination with an alkali metal compound selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof, the mol ratio of the alkali metal compound expressed as the oxide thereof to the oxide of boron in said molten media being within the range from about 1 to about 3.
Claim 10
Dependent Claim
16 words
The process of claim 5 wherein the basicity of the molten media is at least 0.40.
Claim 11
Dependent Claim
14 words
The process of claim 6 wherein the molten media contains an alkali metal borate.
Claim 12
Dependent Claim
24 words
The process of claim 7 wherein the temperature of the molten media is maintained in the range of from about 800* to about 1800*F.
Claim 13
Dependent Claim
25 words
The process of claim 8 wherein the sulfides are contacted with steam at a temperature in the range of from about 800* to about 1800*F.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |